Vinyl playback - lack of bass?

@lewm

Because digital has a brick wall filter at around 22Hz, the response stops dead at the frequency.  ... digital goes very low until it doesn't.  This is not what happens in live music in any real world venue. I cannot get away from the fact that I hear what he was talking about.

I respect your analogue expertise, but your digital explanation seems to have a brick wall of its own!  Brick-wall filters have a very sharp cutoff ...

True, CD quality digital (Red Book specification) is sampled 44,100 times per second.  The highest sinusoidal frequency this can represent is about 22-kHz according to the Nyquist theorem.  To avoid digital artifacts above this frequency, early players did indeed incorporate a very sharp "brick-wall" filter at about 22-kHz to avoid a phenomenon called aliasing.  Smarter manufacturers like Philips expanded the sample rate on playback by creating four samples for every one on the disk.  Philips used a much gentler filter with much better sound quality even on their first players!  This is known as oversampling and is common today.

Of course, much higher recording sample rates are also used today (high-res) and these shift the filter requirement to much higher frequencies.

The ultimate digital format for playback is Direct Stream Digital which starts at 2.8224 MHz and only needs a very gentle low-pass filter to get rid of noise in the mega-Hz frequencies.

There is absolutely no technical reason why digital needs any low frequency cut-off at all. It can simply encode frequencies down to 0-Hz or DC!  So I think you have confused 22-Hz with 22-kHz.

Vinyl record playback systems, on the other hand, have to deal with all sorts of low frequency mechanical resonances which have to be kept below the human limit of audibility generally accepted to be 20-Hz.  I am sure you can list more of these than I can, but top of my list is tonearm resonance, then floor-borne shaking, bearing noise, platter resonance, chassis resonance, mounting board resonance, etc.  To avoid overloading speakers and amplifiers with inaudible low frequencies, analogue playback systems incorporate high pass filters a bit below 20-Hz.

Finally, when a vinyl master is made, the engineer tries to squeeze the grooves as tightly together as reasonably possible to make maximum use of the available 'real estate'.  Infrasonic frequencies would have very large excursions so are filtered out before even reaching the vinyl master.  So I would say "vinyl goes quite low until it doesn't"

@lewm 

I just randomly picked a mid-price CD Player - it happened to be the Marantz CD 60 - and digital playback is down to 2-Hz.  No brick wall at 22-Hz

• USB DSD: 2Hz - 50kHz (-3dB)
  USB PCM: 2Hz - 50kHz (-1.5dB)
  CD: 2Hz - 20kHz

@lewm 

I haven’t “confused” anything. I was referencing early production cdp’s. I thought I said that. Also, of course the term “brick wall” is a metaphor for very steep slope. I probably was remiss in not acknowledging that SACD and DSD ameliorated the problem. But I still hear an unnatural abrupt cutoff of extreme low bass with physical discrete CDs. For whatever reason.

Research doesn’t support me. I was wrong apparently about the low frequency limit built into RBCDs, but I still hear a less natural extreme low frequency response with RBCDs. I have to re-read some 1970s literature to remember why.

No, you simply said digital!

To me this is the perfect example of confirmation bias.  You read something in Stereophile decades ago and now authoritatively state that digital has a low frequency cut-off at 22-Hz, which is completely untrue.  You only have to understand how digital is formatted to understand this.  Or to check out a specification. To the best of my knowledge, there simply is no low frequency limit built into RBCDs, yet you repeat "the low frequency limit built into RBCDs".

You claim you hear this when you go to a concert, so it must be true, but it simply does not exist!

Now it may well be that your digital playback system incorporates a high pass filter somewhere in the chain.  DC offsets are not good for speakers, after all.

This is in no way an attack on you personally, because I have high regard for your analogue contributions, it is just an illustration of how audiophile myths can easily become lore.

@kennyc 

Interesting that Pro-Ject followed Rega down the lightweight turntable path, but Pro-Ject's Signature 12.2 table weighs in at 37-kgs, versus the Rega Planar 6's very lightweight 5-kgs!

My reading is that, for ultimate performance, high mass rules.  There is simply more stuff to absorb unwanted vibrations.  But this means higher costs for materials, finishing, supports and shipping.

I guess Linn is a bit beefier than Rega, but is not really in the heavyweight class.

There is one high-pass filter that I forgot about - the loudspeakers.

I have a Velodyne 18" subwoofer with 1250-Watts RMS power.  It only goes down to about 15-Hz +-3db.

Although my CD player may go down to 2-Hz, even a big subwoofer cannot get close to producing much useful output at anything close to those frequencies.  Velodyne suggest useful output down to 8-Hz.

There are a couple of pipe-organs with 64' pipes which resonate at 8-Hz.  One is down the road from me, in the Sydney Town Hall.  As luck would have it, my partner has just bought a 3-set CD collection including two CDs made with this organ.